THE SHOP

November '18

Issue link: https://nbm.uberflip.com/i/1035833

Contents of this Issue

Navigation

Page 125 of 135

120 THE SHOP NOVEMBER 2018 Always take the time to properly mix plastic filler. Evercoat makes it easy to distribute the right ratio of filler-to-hardener with its Quantum Cartridges. Here Jess Anderson uses an Evercoat cartridge dis- penser to distribute filler and hardener and knows her ratio will be correct. booth is so messy that it starts to affect the quality of your paint work. By that time, it's a half- or all-day project instead of the 15 minutes it would have taken if it had been done regularly. An added benefit: a clean paint booth is also a brighter booth. Sin # 4 MIXING PAINT BRANDS Legendary painter Tom Pre- witt calls it cocktailing paint. For example, using one brand or kind of urethane and a different brand or kind of catalyst. This is usually prompted by a combina- tion of no time and budget constraints. Maybe you're all set up for painting a project and discover you're out of the catalyst normally used. And you have a different brand catalyst from a previous job just sitting there. The problem with committing this sin is that sometimes it works but sometimes it goes very, very wrong. And when that happens, you're looking for a bus to jump in front of. Also, many paint brands have different lines of paint that should never be mixed. For example, PPG has multiple lines of paint. I use its Deltron line. But if I'm using its DCU 2021 urethane, I would never use the catalyst for their DC 2000. One big advantage to using only one line of paint is that you get to know the idio- syncrasies of that particular brand, what to expect, how it likes to be sprayed and just how far you can push it when needed. It's the main reason I've been using the same line of paint for 23 years. PPG makes all kinds of paint, but I stick with Deltron because I know what to expect from it in every situation. And it works great for me. There are so many things that can go wrong when painting anyway, so remove the element of cock- tailing from the equation. Sin # 5 RUSHING BODYWORK & PAINT Cook listed another sin that is also time-related. Many painters do not always wait long enough between coats. One thing I've noticed is that many times painters will apply coats that are far too heavy. What happens in these cases is that basecoats don't get a chance to properly dry before the urethane clearcoat is sprayed. This leads to a number of bad effects, including wrinkling, lifting or paint that remains soft. The least of this sin is the solvents have to fight to get through the curing ure- thane, resulting in severe die back. Die back is what happens when a glassy smooth clearcoat finish turns dull because there was not enough time for the solvent to dry out of the basecoat. Basecoat is not designed to be sprayed heavily and doing so makes it harder for it to dry properly before top-coating. Painting is a chemical process with rules. Paint companies provide product sheets that tell exactly how each product should be applied. Re-coat windows should never be rushed or lengthened. Also, rushing through the bodywork or filler process can turn into a real hassle down the road. I knew a shop that had a big problem shortly before a car was to be delivered to the client. The paint developed lifted areas that turned out to be improp- erly mixed filler. Take the time to thoroughly mix the filler. Don't pile on thick coats. Give it enough time to dry before applying more. It's one of those rules we learn in the beginning, but then we break it all too often. It's easy to think that because we've been doing this for many years just this one time we can break it. But it always comes back to haunt us. It's a rule that I broke once many years ago and never broke again. Sin # 6 NOT CLEANING PANELS PROPERLY Fisheyes are a big painting problem. You clean and clean the panel, then someone goes by the car and leans against it or touches it (usually right after they've eaten fried chicken). Then you're in the booth spraying, and notice the little puckered areas popping up. Fisheyes are caused by a few different things, but the cure is the sameā€”make sure the surface is clean before painting. That means spending extra time pre-cleaning. Once the project is in the spray booth, pre-clean the surface again. And then double-check, carefully going over the surface to make sure nothing was missed. There have been times when I am spraying and I see a spot just as the paint is hitting it. An extra five or 10 minutes of True (Paint) Confessions Here are three differ- ent kinds of PPG Deltron Clearcoat: DC4125 Ceramiclear, DC2000, and DCU2021. Next to each can of clear is the proper catalyst or hardener for that product. Even though they are all from the same line of paint and the cans appear similar, each product is very different and they should never be mixed. Only the catalyst designed for that product should be used. This Harley-Davidson fairing has a terrible case of contamination. It had been pre- cleaned, but then someone wiped it with what they thought was a clean cloth before it went into the paint booth. One more pre-cleaning in the booth would have taken care of this problem. Never trust a surface to be clean; clean it one more time.

Articles in this issue

view archives of THE SHOP - November '18